You may just need a higher level foraging skill. Or keep digging more. The more important question is does he have a spade or pick to mine with. I saw no mention of that.
Yeah it is on my todo list since it is tedious to track down.You could always just allow us to forge kitchen or hunting knives too. Saves you alot of work. Either way thanks!
Just make a camp fire. Do it when there is no rain and keep the horde loaded. Run in a big circle to keep em packed around the fire. If they leave the screen and get unloaded they stop taking damage.